Container



Jan. 6, 1970 R sm ET AL 3,487,989

CONTAINER I5 Sheets-Sheet 1 Filed Jan. 8 1968 Fig.2

Fig.5

Jan. 6, 1970 A, R u m ET AL 3,487,989

' CONTAINER Filed Jan. 8, 1968 s Sheets-Sheet 2 Jan. 6, 1970 A, R usm ETAL 3,487,989

CONTAINER Filed Jan. 8, 1968 5 Sheets-Sheet 3 United States Patent Int.Cl. B6511 23/02, 25/14 U.S. Cl. 229-14 8 Claims ABSTRACT OF THEDISCLOSURE A container structure for liquid contents comprises a linerof PVC, a comparatively stiff outer sleeve of cardboard or polystyreneand an end wall of seamable material such as sheet metal seamed to anend of the liner which projects beyond the end of the outer sleeve andterminates in a seaming flange.

Containers of glass and/or sheet metal have so far mainly been usedwithin the brewery and canning industries for the packaging of theirproducts. Glass bottles or sheet metal cans have thus been used for beerand other aerated drinks. Although it is possible to produce a glassbottle more cheaply than a can of sheet metal, the latter has beenwidely used as a result of a number of factors. For example, a metal canis unbreakable, it has a more compact shape and is absolutely leakproof(a certain amount of gas escaping through the cap of a glass bottle mustalways be allowed for). There has thus been etstablished a big demandfor such robust containers, and it appears that the greatest obstacle toa Wider use of these metallic containers is their comparatively highcost. Attempts have therefore been made to produce containers of the cantype more cheaply by complete or partial use of materials other thansheet metal.

According to an earlier proposed solution, the wall of the cylindricalportion of the container consists of a sleeve of strong cardboard coatedon the inside with a thin aluminium film, while the top and bottom ofthe container are of sheet metal as before. During production of thesecontainers, which are referred to as composite cans in the industry, thesleeve is first inserted into a flanging machine where the edges of thesleeve are folded outwards to as large an extent as is possible withoutthe material of the sleeve bursting. After the sleeve and the lid (orbottom) have been seamed together and the lid folded down along theoutside of the sleeve, the sleeve and the lid will be partially seamedtogether. It has however been found that these composite cans are onlysuitable for very limited excess pressure in the container. When thepressure in the container exceeds the normal value by only acomparatively small amount, the lid or bottom respectively will be blownoff owing to the incomplete folding around the edge of the sleeve.

One of the objects of the present invention is to offer a feasiblesolution to the problem of making beer containers of the can typecheaper. In the same way as in the case of the above described compositecans, a combination of a sleeve of some cheap material, for instancecardboard, a lid and/or a bottom of sheet metal or some comparablematerial that is capable of being seamed, and a liner which is leakproofand resistant to the proposed contents, are utilized. The characteristicfeatures of the invention are that the lining extends past the edge(s)of the sleeve and that the projecting portions of the lining are in aleakproof and durable manner seamed together with the lid and/ orbottom. The sleeve will in this way be relieved of axial tensilestresses set up by the pressure in e CC the container, these tensilestresses being on the whole completely transferred to the lining. Sinceit is easy to make the lining of such material that can easily be seamedon to the ends and which in addition satisfies requirements as regardstensile strength, leakproofness and resistance to the contents, therearises in this way a possibility of producing a packaging containerwhich, apart from being cheap to produce, also has all the advantages ofthe can type container.

The lining is preferably made of a plastic material, a combination ofseveral plastic materials, or of a combination of plastic and forinstance aluminum. It has been proposed before that beer cotnainersshould be produced from polyvinylchloride (PVC) in the shape of twohollow bodies welded to one another. It has further been proposed beforethat beer containers should be produced that the side of the plasticmaterial which is to form the inside of the container should bevarnished with polyvinylidene chloride. Since, however, it is notpossible to seal polyvinylidene chloride by conventional weldingmethods, it has not been possible to apply these principles in practiceunless spaces are left in the material for the weld. By the presentinvention, however, which is not based on welding as the method ofclosure, it will be possible to make use of the material compositiondesired, which is one of the advantages of the invention.

In accordance with one preferred constructional form of the invention,the lining consists of a hollow body having a jacket of circular crosssection, a hemispherical bottom portion and an opening, the hollow bodyhaving been produced by means of deep-drawing fiat PVC (which may becovered by polyvinylidene chloride varnish). During the process ofdeep-drawing, the material is forced into the forming tool, whichresults in the formation of an outward-turned flange around the openingof the hollow body. This flange, in accordance 'with the presentinvention, is used to seam the lining on to the lid, Owing to the factthat the flange is formed right at the beginning, it is possible to savea stage in working operations which otherwise would be difllcult toeliminate, and since in addition only one sheet metal end wall isrequired as against two in the case of the composite cans previouslyproposed, the use of the prefabricated deep-drawn lining can furtherreduce the cost of the end product.

In the canning industry also, the predominant packaging materials haveso far been glass and sheet metal. This is particularly so in the caseof processed foods for several reasons, some of which are therequirement that the packaging material should be absolutely leakproof,the requirement that the material should be capable of withstandinglong-term heating in an autoclave, and the requirement that the materialshould be capable of closure (capable of being welded, usually). Acontainer produced in accordance with one of the constructional forms ofthe invention satisfies all these requirements. In accordance with thisconstructional form, the lining consists of a laminate containing, inaddition to at least one plastic layer, also a layer, preferablyaluminium, that has satisfactory barrier characteristics towards thecontents. This composition is capable of withstanding longterm heatingwithout being deformed or damaged in some other way and is also suitablefor seaming on to the lid. The lining is preferably produced by foldingflat material so as to obtain a hollow shape having a cylindricalportion, a flat or curved bottom and an outward-turned flange around theopening of the body.

The invention will now be more closely explained by reference to theenclosed drawings, of which FIGURES la to c show exploded perspectiveviews of the various components making up the container in accordancewith a first constructional form of the invention, these being FIG. 1ashows a sheet metal lid,

FIG. 1b shows a lining in the shape of a prefabricated hollow bodyhaving a curved bottom, a cylindrical wall and a flange, and

FIG. 1c illustrates a cardboard sleeve.

FIG. 2 shows diagrammatically the starting point of the operation ofseaming the sheet metal lid on to the flange of the lining,

FIG. 3 shows the finished connection,

FIG. 4 illustrates how the connection can be supplemented by the use ofadditional sealing material,

FIG. 5 shows (partially exposed) the finished container in accordancewith the first constructional form,

FIGS. 6 and 7a to 70 illustrate the production of a container inaccordance with a second preferred constructional form of the invention,in which the material for the lining is initially a tube protruding outof both ends of the sleeve,

FIG. 7a shows a sheet metal lid for this,

FIG. 7b a sleeve with the lining, which has been folded out at bothends, in position, and

FIG. 7c a sheet metal bottom,

FIG. 8 shows the finished container produced in accordance with thesecond constructional form of the invention,

FIG. 9 shows a lining produced by folding a flate material, and

FIG. 10 shows an enlarged view of the structure of the flange of thislining.

The sheet metal lid 1 shown in FIG. 1a has a flat, somewhat depressed,central portion 2. The depth of this depression has been exaggerated inthe figure in order that the nature of the construction may be moreeasily seen. The lid also has a flange with a back 3 and a shoulder 4which projects downwards and inwards. The material which is capable ofbeing seamed may also be polystyrene as an alternative to sheet metal,the polystyrene being impact-resistant.

The lining 5 in FIG. lb consists of a deep-drawn hollow body of PVCwhich may, on the inside, be varnished with polyvinylidene chloride. Thelining has a cylindrical body 6 and a curved, preferably hemisphericalbottom 7. The cylindrical portion becomes an outward-turned flange 8around the edge of the opening.

The outer sleeve 9, FIG. 1a, consists mainly of cardboard 10 but is inaddition preferably provided with a label 11, FIG. 2, which extendsright up to the upper edge of the sleeve. It is best if the labelcontains a plastic layer or an aluminium film, or is coated with aplastic varnish, so that sleeve 9 will not become saturated during thefilling operation. The sleeve may as an alternative to cardboard consistof extruded polystyrene, which is particularly suitable when thecontents of the container are to be pasteurised.

The principles of the seaming together of the lid and the lining shouldbe apparent from FIGS. 2 and 3. The operation will however be furtherclarified in the following description.

The main body 2 of the lid 1 is situated below the upper edge of sleeve9. From this lower level (the depth of which, as referred to earlier,has in the figure been exaggerated) the edge zone portion of the lid,together with the uppermost portion of the lining, at first extends upwards to the level of the upper edge of sleeve 9. From this point back 3runs along the flange 8 of the lining. The shoulder 4 projects past theouter edge of flange 8.

The seaming operation may be carried out by means of conventionalseaming machines. In this operation, rollers of the appropriate sectionare rotated at speed round the edge of the lid, at the same time as theymove in towards the center of the can, subjecting it to a Spinningaction. Since the cold-worked sheet metal can only spring back to aninsignificant extent, there is set up a very high pressure between thematerials which have been seamed together. It is in this connection ofadvantage if, in some conventional way, the sheet metal lid is coatedwtih some kind of sealing agent 12, FIG. 4, for instance a compound suchas strong plastic PVC, which after seaming will effectively fill all thepores.

As a result of the seaming operation, shoulder 4 of the lid will befolded in underneath the outward-turned flange 8 of the lining, and theback 3 of the lid, together with the said flange 8 and shoulder 4, willbe folded down along the outside of sleeve 9 and will also be pressedinto the material of the sleeve so that this will be compressed. Whenthe centents of the container exert excess pressure, which may beconsiderable when the contents are an aerated liquid, all the walls willthus be subjected to an outward force. The outward force acting on thebody 6 of the lining will be resisted by the strong outer sleeve 9. As aresult of the pressure on the end walls, namely the curved bottom 7 andthe lid 1, axial tensile stresses will be set up partly in thecylindrical wall 6 of the lining and partly in the connection betweenthe cylindrical wall and the lid. The former can be countered by meansof suitably dimensioning the wall thickness, while the latter iscountered by the shape of the connection between the lid and theremainder of the container, which is a characteristic of the invention.As will be appreciated from a study of FIG. 3, sleeve 9 is on the wholecompletely relieved of axial tensile stresses, which will instead betaken up by the lining which is joined to the lid by means of a verydurable connection that may almost be described as a hook-joint.

The appearance of the finished container should be quite clearlyapparent from FIG. 5. The lower end of the sleeve is turned inwardly andup and forms the base of the container.

In the constructional form shown in FIG. 8, the material for the liningis initially a tube 15 of the same material in the case of the previousconstructional form. The sleeve 9 is the same as before. Portions 16 and17 of tube 15 project past both ends of sleeve 9. In order that thejointing to the lid and bottom respectively may be facilitated, it isbest if portions 16 and 17 are folded outwards to form flanges 16' and17', FIG. 7b, corresponding to flange 8 in the previous constructionalform, which in the case of suitable material will occur spontaneouslywhen heat is applied. A sheet metal lid 1 and a sheet metal bottom 1 ofthe same kind as the sheet metal lid in the previous constructional form(or alternatively impact-resistant polystyrene or some other materialcapable of being seamed) is used for the closure of the container.

Since seaming together of the tubular lining 15 and sheet metal endwalls 1 and 1' may be carried out in a way analogous to that describedearlier, there should be no need for any further description of thisprocess.

A lining 24 for containers which are designed to be used for thepackaging of preserved foods is shown in FIG. 9. Owing to the fact thatPVC shrinks when heated, this material is not suitable for this purpose.The lining is instead produced from a laminate containing an aluminumlayer which possess the required barrier characteristics, and apolyethylene layer on each side of the aluminum layer, the plastic beingmainly the reason for the material having a certain mechanical strength.The mate- .rial is initially flat and is then folded to attain the shapeshown in the figure. The surface of the body, namely its curved (or insome cases flat) base 19, cylindrical wall 18 and outward-turned rflange20 will thus exhibit alternating valleys and ridges. In certain cases,viscose cellulose (cellophane) may also be considered as an alternativeto aluminium. The pleated liner structure is also disclosed and claimedin a co-pending application Ser. No. 675,549, filed Oct. 16, 1967, nowUS. Patent No. 3,436,007.

Au enlargement of portion of flange 20 is shown in FIG. 10. Thealuminium layer, whose fold pattern should with the desired degree ofclarity be apparent from the figure, has here been denoted 21. The foldpattern has been fixed by means of melting together the plastic material22. Owing to the fact that heat and pressure are simultaneously appliedover the flange 20, a substantial evening-out of the fold pattern isattained here, but it is difficult to even out completely the materialin thisway. The remaining depressions in the material have been denoted23 in FIG. 10. It should be appreciated thatthese valleys constitute adanger to the leakproofness of the container if the conventional weldingis applied, insofar as they may form direct channels between the insideof the container and the surroundings. If however the container isclosed by means of a sheet metal lid or in some corresponding manner) inthe way described in the foregoing, namely by the use of appreciablecompressive forces, all irregularities will be eliminated and a veryleakproof package will be obtained. A tube of extruded polystyrene orcomparable water-resistant material is in this case used as outersleeve.

What we claim is:

1. In a container structure for liquid contents the combinationcomprising an inner liner constituted by a three layer laminatecomprising two outer layers and an inner layer having a barriercharacteristic with respect to the contents, an outer sleeve ofcomparatively stiff and essentially non-metallic material surroundingand in contact with said inner liner, at least one end portion of saidliner projecting beyond the corresponding end of said sleeve, and a lidof seamable material seamed to said projecting end portion of said linerand which establishes an end wall of the container.

2. A container structure as defined in claim 1 wherein said outer layersof said liner are made from polyethylene and said inner layer is madefrom aluminum and wherein said outer sleeve is made from cardboard andsaid lid is made from sheet metal.

3. A container structure as defined in claim 1 wherein said outer layersof said liner are made from polyethylene and said inner layer is madefrom aluminum and wherein said outer sleeve is made from polystyrene andsaid lid is made from sheet metal.

4. A container structure as defined in claim 1 wherein the projectingend portion of said liner terminates in an outwardly turned flange whichis seamed together with a flange portion of said lid.

5. A container structure as defined in claim 1 wherein the top end ofsaid liner is closed by said seamed-on end wall and the bottom endthereof is integral with the side walls which has a cylindricalconfiguration.

6. A container structure as defined in claim 1 wherein said inner lineris constituted by a tube projecting from both ends of said outer sleeve,and each end of said tube is closed by a seamed-on end wall.

7. A container structure as defined in claim 1 wherein the seamedtogether parts of said end Wall and liner are folded down over theoutside of said sleeve.

8. A container structure as defined in claim 1 wherein the seamedtogether parts of said end wall and liner have the shape of ahook-joint.

References Cited UNITED STATES PATENTS 1,955,745 4/ 1934 Hurley.1,993,751 3/1935 Reid. 2,110,612 3/1938 Skinner et al. 2,141,499 12/1938Williams. 2,200,200 5/ 1940 Donnelly. 2,711,382 6/1955 Smith et al.156-227 3,129,867 4/ 1964 Schroeder. 3,313,440 4/ 1967 Nofer 229--5.6 XR3,355,080 11/1967 Rausing et a1.

DAVIS T. MOORI-IEAD, Primary Examiner US. Cl. X.R. 156-227; 2295.6

